The method according to the invention is designed for a known automatic machine in which a plurality of test fluids can be analyzed in sequence. These test fluids can contain microorganisms and usually are delivered to the automatic machine in cuvettes from which the automatic machine takes the test fluid with the help of a pipette in order to load them into the measuring chambers of so-called microtitration plates. The measuring chambers can be loaded with a nourishing solution and/or detection chemicals for certain microorganisms. Before the test fluid can be loaded into the microtitration plate, it must as the case may be, be preprocessed, for example, be homogenized or thinned. The homogenization can, for example, take place with the help of an ultrasonic mixer. However, the danger exists that an atomized spray of the test fluid can escape from the cuvette opening. Because of this, the cuvette cover must be closed at least during the homogenization process. With this the problem arises that the cover itself becomes dirty and with a change of cuvettes microorganisms can be transmitted from one cuvette to the following cuvette by the cover. Naturally this must be avoided under all circumstances.
One solution exists in that the cover surface is wiped off with each cuvette change. A wiping mechanism necessary for this is not only complicated but also does not solve the problem since the washing organ itself must also be disinfected in order to avoid a spreading of the microorganisms. With the use of disinfecting chemicals there exists the danger of a contamination of the test fluids and a damaging of the microorganisms contained in the fluids.
The invention has as its object the provision of a method by means of which the cover surface can be disinfected reliably in a simple way.